In this paper, the effects of silane treatment on the bond characteristics of fibre in a cementitious matrix, including the bond strength, pullout energy, etc., are presented. These fibres were obtained from recycling by crushing of a thermoset composite based on unsaturated polyester/glass fibre. The experimental results of the fibre pullout test under different conditions are reported. Silane treatment contents between 0% and 1% are used, and single fibre pullout tests are conducted to measure the bond characteristics of the fibre to the cementitious matrix. It is found that the silane treatment (VTMO) can effectively enhance the fibre–matrix interfacial properties, especially the fibre pullout energy. It is also concluded that in terms of the bond characteristics, the optimal silane content is 0.5%, given the conditions of this experimental program. Microstructural observation confirms the findings on the interfacial-toughening mechanism drawn from the fibre pullout test results.